Improvement in jewelers lathes



N W. HOLT.

.lewalers 'Latho.

Pdtented Jan. 26 1875.

II n FIG 8.

WITNESSES.

UNITED STATES TENT F NEWTON W. HOLT, OF BENNINGTON, VERMONT, 'ASSIGNOR TO OLIN SCOTT,

" OF SAME PLACE.

IMPROVEMENT l N JEWELERS LA'l'HES.

Specification fofiiiiiig part of Lctters'Pa tit'No.I'5EFJ1'Q0; dated January 26, 1875; application filed SeptemberQS, 1874. I

' of the supporting-standard,driving-wheel, and

rotary head-stock which carries the various cutters, mandrels, or spindles to be operated. Fig. 2 shows a front elevation of the lathe, and Fig. 3 exhibits a plan of the top of the head-stock.

The lathe consists of a. tripod,..provided.at.

its upper end with a clamp-socket, which rewives and supports the standard to which is attached the friction driving-wheel, and upon and about the top end of which revolves the rotary hea(l-stocl;,with its various attachments.

By reference to Fig. 2 of the drawing, it will be seen that the socket of the tripod or stand B is provided with two jaws, between which revolves thepinion-gear O. The shaft of this gear is made with a shoulder on the crank end, and a. nut on the opposite end, and passes through both jaws or cheeks of theclamp B, and is so arranged that the standard A may be raised and depressed by turning the gear 0, which works in the rack S upon the standard, till any desired elevation is attainethwhen, by turning the aforesaid nut on the gear-shaft, the clamp is tightened and the standard firmly held in place. The collar Dis applied at lower end of the standard to limit its elevation.

Upon the standardA a stud, J, is constructed, upon and about which revolves the drivingwheel T. The periphery of this wheel is grooved to receive a rubber, leather, or other friction-band, by means-of which the pulleys upon the several spindles of the head above are driven. This driving-wheel is provided with a crank-pin, by which and the adjustable pitman L M K and treadle or foot-lever the same is driven. The pitman consists of the upper portion or rod L, attached to the crankpin, and the hollow or tubular portion K, which is attached to the foot-lever, and which receives and-retains the part L after adjustment. -Aiter adjustment the several parts of standard, .for a short space below the head-j stock, is threaded to receive the nut E. Be-

tween this nut and the head-stock G is the collar F. ,Upon' the topof the standard the collar H is fastened securely by set-screws or otherwise, and between this collar and the upper surface of the head-stock is placed the rubber spring or cushion 0, against which the nut E Works to regulate the degree of pressare or friction between the rim I of the driving wheel T and the pulleys of the several spindles N X Y Z. By running the nut down the pressure is increased, and vice versa. The collar H has a projecting arm, Q, through the I extremity of which the pin P passes, and into the holes UU U of .the head-stock G. The oflice of this device is to secure or lock the head-stock when some one of the spindles has been brought into position to be operated by the driving wheel. The spindles N X Y Z are arranged radially about the center of the head-stock G. The inner bearings of said spindles are located in the hub of the headstock, and the outer ones are constructed in bushings a a a, which are inserted in the periphery of the head-stock. The inner bearifgs of the spindles are provided with oilholes V V V for facilitating the lubrication of in an annular chamber constructed therefor on the under side of theheiul-stock. These pulleys may be of different diameters, so as to obtain different velocities from the same dtiving-wheel, as they can readily be brought into contact with the driving-wheel T, and be adjusted by means of the threaded standard A, nut 1*], spring 0, and collars F and ll. The periphery of the headstock is perforated where the spindles pass through, and bushings amt are inserted, which form the outer bearing of the spindle.

This lathe is designed for and adapted to the usesfor which jewelers, dentists, and other mechanics require asmall portablelathc and the advantages claimed for it are that the retatable head can be provided with as many and as various devices for doing circular Work as the diverse natures of the several. trades or occupations may require. In the drawing E have shown a face-plate and centers, mandrels, a screw-center, 850. "Where it becomes necessary to employ several agencies or tools in making or finishing the same piece of work, as, for instance, a chuck, an emery-wheel, buffer, a knnrl, and a finishingwheel, these may all be arranged on separate centers or spindles, and may be successively brought collars F and II. head-stock G, eollarspring as shown in Figs. 1, 2, and 3,. and operating substantially as described.

The threaded standard A, nnt E, rotary head-stock G, collar-spring 0,0ollars' F and H, radial spindles N X Y Z, and driving-wheel Ci, attached to the standard A, as shown and described.

3. The within-described means of regulating the degree of friction necessary to operate and bring into adinstinent the several spindles attaehed to the head G, when the same are provided with pulleys of difi'erent diameters to obtain different velocities. and consisting of the threaded standard A, nut E, collar H, spring 9, and head-stock G, conjointly operating and constructed as shown.

at. The wertioally adjustable standard A, driving-wheel T, and adjustable socket-pitnian K L M, combined and operating as described.

In testimoitiy whereof I have hereunto sub scribed my name.

' NEWTON W. HOLT.

Witnesses:

(inns. W, BENTON, Annnnw M, Barns. 

